Drawing-tables with vertically adjustable drawing-board



July 10, 1962 P. G. BERGMAN DRAWING-TABLES WITH VERTICALLY ADJUSTABLE DRAWING-BOARD Filed Sept. 30, 1959 INVENTOR Per Gotthold Bergman lRJ- FLocKs ATTORNEY 3,643,643 DRAWING-TABLES WITH VERTICALLY ADJUSTABLE DRAWING-BOARD Per Gotthold Bergman, Hyggevagen 21, Spanga, Sweden Filed Sept. 30, 1959, Ser. No. 843,480 9 Claims. ((11. 45-131) This invention relates to a drawing-table with a vertically adjustable drawing-board which is carried by supporting arms pivotally mounted on a supporting shaft in said table, the inclination of the drawing-board being maintained constant, at the vertical adjustment of said drawingboard, by means of a parallel motion mechanism.

The previously known drawing-tables of this type take up a considerable space. The present invention eliminates this disadvantage and is characterized by the fact that the drawing-board supporting arms are so bent that the parts thereof which adjoin the supporting shaft are substantially horizontal while the parts of said supporting arms which adjoin the drawing-board are directed upwardly when the drawing-board occupies its uppermost position, whereby a table top or the like located behind the drawing-board and above the supporting shaft can extend such a distance inside said supporting shaft that the edge of the table top facing the drawing-board lies in immediate proximity to said drawing-board.

Further features of the invention and the advantages in its lowermost position.

With reference to the drawing, 1 designates the drawing-table proper or the frame thereof, and 2 designates the drawing-board which is vertically adjustably mounted on the drawing-table. The drawing-board is carried by supporting arms 4 which are pivotally mounted on a supporting shaft 3 in said table 1. The drawing-board 2 cooperates with a parallel motion mechanism which ensures that the inclination of the drawing-board 2 is maintained constant at the vertical adjustment thereof.

According to the invention, the supporting arms 4 are so bent that the parts 5 of said arms which adjoin the supporting shaft 3 are substantially horizontal While the parts 6 of said arms which adjoin t-he drawing-board 2 are directed upwardly when the drawing-board 2 occupies its uppermost position. By this arrangement a table top 7 or the like located behind the drawing-board 2 and directly above the supporting shaft 3 can extend such a distance inside the supporting shaft 3 that the edge of said table top facing the drawing-board 2 lies in immediate proximity to the drawing-board 2 or its extension. In drawing rooms and like premises where several drawing-tables are placed behind each other in a row, it is thus possible, upon application of the present invention, to exploit the floor space better than heretofore.

In a preferred embodiment the angle between the parts 5 and 6 of the supporting arm 4 is approximately a right one so that the part 6 is substantially vertical when the drawing-board 2 occupies its uppermost position, the front edge of the table top 7 lying almost in the angle between the parts 5 and 6.

In the embodiment according to FIGS. 1 and 2 the 3,43,@48 Patented July 10, 1962 parallel motion mechanism is a parallelogram of which the supporting arm 4 is a constituent part. The bar 8 in said parallelograms are parallel with the mounting points of the supporting arms 4 and provided each with one extension to which a balancing counterweight 9 is secured.

As will appear from the embodiment according to FIGS. 1 and 2, the supporting arms 4 and the parallelogram bars 8 in the lowermost position of the drawingboard 2 will be located in a low position, which will inconvenience the draftsmen when seated. This disadvantage has been eliminated in the embodiment according to FIGS. 3 and 4. In this latter embodiment at least one of the supporting arms 4 forms, together with two bars 10 and 11 and an angle piece 12, two parallelograms which constitute the parallel motion mechanism and which are'adapted, upon lowering of the drawing-board 2, to pivot downwardly and rearwardly. This will give an increased space beneath the drawing-board 2.

In the embodiment shown in FIGS. 3 and 4, the drawing-board 2 is balanced by torsion springs in lieu of a counterweight.

For a change in its inclination the drawing-board 2 is pivoted about the shaft 13, a torsion spring lying in or in the vicinity of the shaft 13 being suitably used for balancing the drawing-board.

While the invention has been described in the foregoing in two preferred embodiments it is understood that it is not limited to these very embodiments, as various modifications can be resorted to Within the scope of the appendant claims.

What I claim and desire to secure by Letters Patent is:

l. Drawing-table with a vertically adjustable drawingboard carried by supporting arms pivotally mounted on a supporting shaft in said table, the inclination of the drawing-board being maintained constant, at the vertical adjustment of said drawing-board, by a parallel motion mechanism, characterized by the fact that the supporting arms are so bent that the parts thereof which adjoin the supporting shaft are substantially horizontal while the parts of said supporting arms which adjoin the drawing-board are directed upwardly when the drawingboard occupies its uppermost position, whereby a table top or the like located behind the drawing-board and above the supporting shaft can extend such a distance inside the supporting shaft that the edge of said table top facing the drawing-board lies in immediate proximity to the drawing-board.

2. A drawing-table as claimed in claim 1, characterized by the fact that the angle between the parts of the supporting arms adjoining the supporting shaft and the parts of the supporting arms adjoining the drawing-board is approximately a right angle so that theparts of the supporting arms which adjoin the drawing-board are substantially vertical when the drawing-board occupies its uppermost position.

3. A drawing-table as claimed in claim 1, characterized by the fact that at least one of the supporting arms is a constituent part of a parallelogram forming said parallel motion mechanism.

4. A drawing-table as claimed in claim 1, characterized by the fact that at least one of the supporting arms forms, together with two bars and an angle piece, two

parallelograms which constitute the parallel motion mech-' anism and which are adapted, upon lowering of the drawing-board, to pivot downwardly and rearwardly.

5. A drawing-table comprising a vertically adjustable drawing-board, a table, a supporting shaft positioned in said table, supporting arms pivotally mounted on said supporting shaft and said drawing-board, said supporting arms in the shape of approximately right angle members, supporting bars pivotally connected torsaid drawingboard at a point below the pivotal point of said supportporting arms and said drawing-board, said supporting bars also pivotally connected to said table at a point lower than said supporting shaft, and means to counterbalance the weight of said drawing-board whereby said drawingboard' is maintained at' a constant angle of inclination regardless of its vertical adjustment. I

6.'The drawing-table of claim 5, further including a spaapae pivotal adjustment at the pivot pointtof said supporting arms and said drawing-board whereby the inclination of said drawing-board may be changed.

7. A drawing-table with a drawing-board which is vertically adjustable in front of the table by means of 'a parallel motion mechanism, said parallel motion mechanism being mounted on said table and connectedto said drawing-board and being provided with an upper arm and a' lower arm, said upper arm being bent angularly and upwardly, the upper arm in its uppermost position having a portion thereof extending generally horizontally beneath the table top, said upper arm having a pivot point on the drawing board and a pivot point on said table, the arms being of such length and the upper arm so bent that with the drawing board in its uppermost position, a line References Cited in the file of this patent UNITED STATES PATENTS 1 ,568,850 Koch Jan. 5, 1926 1,907,780 Froelich' May 9, 1933 v FOREIGN PATENTS '1 491,295 Great Britain Aug. 30, 1938 719,799 7 Germany Mar. 19, 1942 :France Mar. 26, 1947 

